The present application is related to U.S. Pat. application Ser. No. 07/400,710 filed Aug. 30, 1989.
This application relates to an improved cargo container adapted for use for either air or ground transport having components which are simple to assemble and disassemble and a construction which is tolerant of flexing and deformation of the panels and frame.
The use of transparent panels is disclosed by U.S. Pat. No. 4,833,771 issued May 30, 1989 to Dunwoodie. These panels are held by inner and outer corner moldings and therefore require custom fabrication of the edges of the panels to accommodate the shape of the inner and outer molds. Such processing of the panel edges necessarily introduces stresses in the panel edges which can lead to failure of the panels during use. Nuts and bolts are used to attach the inner and outer corner moldings together over the panel edges.
A shipping container capable of being assembled without tools, ie. without nuts and bolts or other like fasteners, is disclosed in U.S. Pat. No. 3,517,849 issued to Presnick. Presnick uses extruded frame members with elongated slots to receive the edges of a rigid panel and corner members with legs to fit into the hollow ends of the extruded frame elements. The frame elements matingly couple to each other so that a panel enclosed by frame elements and corner members interlocks with a panel and surrounding frame element and corner members corresponding to each one of the elongated edges of the panel. The Presnick assembly is not water tight at the edges proximate the corner pieces since it is not cemented to the corner pieces. Moreover, the latter assembly is not highly deformation tolerant as deformation puts a strain on the edge joints and the rigid panels themselves. Finally the panels of Presnick can not be removed without first disassembling at least in part the frame structure.
Italian Pat. No. 623,118 issued July 7, 1961 to J. Langham Thompson Group Limited discloses a knockdown container assembly with corner pieces having legs dimensioned to fit into the ends of extruded frame elements and panels which are attached by screws to the extruded frame elements. The corner pieces consist of an outside rounded piece with a bolt and the inner corner piece with a bolt hole and a nut threaded onto the bolt to hold the inner and outer corner piece together.
The utilization of rigid panels with edges either glued to the frame elements or fastened thereto with screws makes the known cargo containers susceptible to fracture of the panels or failure of the edge joint on being deformed in response to an applied load. Since it is common practice to apply large loads to the inside walls during filling of a container which can cause deformation of the container and subsequent failure, such assemblies tend to have a relatively limited life when used as airline, truck or ship containers.
Accordingly, it is an object of the present invention to provide an improved cargo container. It is yet a further object of the invention to provide such a container that is better able to withstand deformation than hitherto known containers. Yet another object of the invention is to provide a container which is substantially water tight.